/kloc-in the 8th century, French mathematicians Buffon and leclerc put forward the problem of throwing needles, which was recorded in Buffon's book published in 1777: "Draw a set of parallel lines with a distance of d on the plane, and put the length of L (L

P=2l/(πd) π is π.

Using this formula, the approximate value of pi can be obtained by probability method. Here is some information.

Pi estimation of the intersection times of the annual throwing times of the experimenter

Wolf1850 5000 25313.1596

Smith1855 32041219 3.1554

De Morgan 1680 600 383.438+037

Fox 1884 654438

lazzerini 190 1 3408 1808 3. 14 15929。

Lai Na 1925 2520 859 3.6438+0795

Buffon's throwing needle experiment is the first example of expressing probability problems in geometric form. He used random experiments to deal with deterministic mathematical problems for the first time, which promoted the development of probability theory to some extent.

Like the needle throwing experiment, we use the probability obtained through the probability experiment to estimate a quantity we are interested in. This method is called Monte Carlo method. Monte Carlo method rose and developed with the birth of computer during the Second World War. This method is widely used in applied physics, atomic energy, solid state physics, chemistry, ecology, sociology and economic behavior.